Driving method, driver circuit and design method of driver circuit for in-cell touch display panel

ABSTRACT

A driving method, a driver circuit and a designing method of a driver circuit for an in-cell touch display panel are provided. The driving method includes: connecting all horizontal scan lines of the touch display panel to a first GOA circuit, the first GOA circuit performing display scanning according to a preset timing sequence; and after completing each time of TP scanning according to preset timing sequence, a first horizontal scan line in a following scanning according to preset timing sequence still connected to a second GOA circuit, the second and first GOA circuits synchronously performing display scanning to the first horizontal scan line. The driving method, driver circuit and design method of driver circuit for in-cell touch display panel provided by the invention solve the dark line problem appearing in time-sharing scanning between display and TP terms for in-cell touch display panel, and improve display quality.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional application of co-pending patent application Ser.No. 15/117,455, filed on Aug. 9, 2016, which is a national stage of PCTApplication No. PCT/CN2016/090112, filed on Jul. 15, 2016, claimingforeign priority of Chinese Patent Application Number 201610417491.9,filed on Jun. 12, 2016.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to the field of display, and in particularto a driving method, driver circuit and design method of driver circuitfor in-cell touch display panel.

2. The Related Arts

As the display technology rapidly develops, the touch display panel iswidely accepted and used in many applications, such as, smart phone,panel PC. The touch display panel uses embedded touch control technologyto integrate the touch control panel with liquid crystal display (LCD)panel, and embed the functions of touch control panel into the LCD panelso that the LCD panel can both display and detect the touch controlinput.

To realize the thin design of electronic products, the display screensused in the smart phones and panel PCs are mostly capacitive touchcontrol screens. Based on the structure, the capacitive touch controlscreens can be categorized into on-cell type, hybrid in-cell type andfull in-cell type, wherein the on-cell type has the touch controlelectrodes on the liquid crystal (LC) box (i.e., cell), the hybridin-cell type has the touch control electrodes in the LC box, and thefull in-cell type also has the touch control electrodes in the LC box.Comparing the last type to the other two types, the full in-cell typeenables further better thin design in the display screen. The hybridin-cell and full in-cell type touch display panels are both touchdisplay panel with the touch control electrode embedded in the LC box,and provide advantages of lower cost, ultra-thin design and narrowborder, and are mainly for high-end products. As such, the in-cell typeis evolved to become the mainstream for future touch control technology.

On the other hand, the operating principle of the LC panel is asfollows: disposing LC molecules between two parallel glass substrates,and applying a driving voltage on the two glass substrates to controlthe rotation direction of the LC molecules to reflect the light emittedfrom the backlight module to display images. In the active LCD panel,each pixel comprises a thin film transistor (TFT), with the gateconnected to a horizontal scan line (gate line), the drain connected toa vertical data line, and the source connected a pixel electrode. Byapplying a sufficient voltage to the horizontal scan line, all the TFTson the line will be turned on so that the pixel electrode of thehorizontal scan line will be connected to the vertical data line so asto write the display signal on the data line into the pixel to controlthe transmittance of the different LCs to achieve color control. Atpresent, the common approach is to manufacture the driver circuit of thehorizontal scan line in the gate-on-array (GOA) circuit at the activearea peripheral on the substrate to achieve driving the horizontal scanline.

As shown in FIG. 1 of a schematic view of driving timing sequence for aknown in-cell LCD, the scan time for a frame is 16.7 ms, and the reportrate of the touch control is 60 Hz. At present, for the in-cell LCD,such as full in-cell LCD, the small-to-medium size low temperaturepolysilicon (LTPS) LCD mainly uses display and touch panel (TP)time-sharing driving scan approach: i.e., a gate scanning N lines,followed by scanning apportion of TP, and following by another gatescanning N lines, and so on, until a frame finishes displaying. Theadvantage of this approach is a less interference between the displayand TP.

However, as shown in FIG. 2 of a schematic view of a dark line appearingafter TP scanning or a known in-cell LCD, at the handover between thedisplay term and the TP term (i.e., display term ends and TP termstarts), the gate is in a holding state of low voltage (VGL), and thesource is in a holding state of ground (GND). After a long time, thecurrent leakage will occur. After TP scanning is complete and thescanning of (N+1)-th line starts, the gate signal of the (N+1)-th linewill become as shown in FIG. 3 due to the current leakage. FIG. 3 is aschematic view of the gate signal transmitted for a known in-cell LCD.At this point, the signal is distorted (serious delay for rising andfalling edges). As such, the gate signal of the (N+1)-th line isinsufficient to push the (N+1)-th pixel to fully charged, leading to alower luminance of the (N+1)-th line and resulting in a dark line.

FIG. 4 is a schematic view showing the known the GOA single side drivingcircuit. In the current small-to-medium size LCDs, the gate drivingstructure is mostly a single-sided GOA driving. The GOA circuit 1 isconnected to each horizontal line and scan the gate of the first line,the gate of the second line, . . . , the gate of the N-th line, the gateof the (N+1)-th line . . . , respectively, following the preset timingsequence.

Therefore, it is desirable to provide a new driving structure to addressthe dark line problem appears in the time-sharing scanning betweendisplay and TP terms in the in-cell touch display panel.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a driving method forin-cell touch display panel, able to solve the problem of the dark lineproblem appearing in the time-sharing scanning between display and TPterms in the in-cell touch display panel, and to improve displayquality.

Another object of the present invention is to provide a driver circuitfor in-cell touch display panel, able to solve the problem of the darkline problem appearing in the time-sharing scanning between display andTP terms in the in-cell touch display panel, and to improve displayquality.

Yet another object of the present invention is to provide a designingmethod for the driver circuit for in-cell touch display panel, able tosolve the problem of the dark line problem appearing in the time-sharingscanning between display and TP terms in the in-cell touch displaypanel, and to improve display quality.

To achieve the above object, the present invention provides a drivingmethod for in-cell touch display panel, which comprises:

Step 10: connecting all horizontal scan lines of the touch display panelto a first GOA circuit, and the first GOA circuit performing displayscanning according to a preset timing sequence; and

Step 20: after completing each time of touch panel scanning according tothe preset timing sequence, a first horizontal scan line in a followingscanning according to the preset timing sequence being still connectedto a second GOA circuit, the second GOA circuit and the first GOAcircuit synchronously performing display scanning to the firsthorizontal scan line.

In a preferred embodiment, the touch display panel is a hybrid in-cellLCD.

In a preferred embodiment, the touch display panel is a full in-cellLCD.

In a preferred embodiment, the first GOA circuit and the second GOAcircuit are located respectively at two opposite sides of the touchdisplay panel.

In a preferred embodiment, the first GOA circuit and the second GOAcircuit have a thrust passing simulation confirmation in advance.

To achieve the above object, the present invention also provides adriver circuit for in-cell touch display panel, which comprises: a firstGOA circuit, and a second GOA circuit; the first GOA circuit beingconnected to all horizontal scan lines of the touch display panel, andperforming display scanning according to a preset timing sequence; andafter completing each time of touch panel scanning according to thepreset timing sequence, a first horizontal scan line in a followingscanning according to the preset timing sequence being still connectedto the second GOA circuit, the second GOA circuit and the first GOAcircuit synchronously performing display scanning to the firsthorizontal scan line.

In a preferred embodiment, the first GOA circuit and the second GOAcircuit are located respectively at two opposite sides of the touchdisplay panel.

In a preferred embodiment, the first GOA circuit and the second GOAcircuit have a thrust passing simulation confirmation in advance.

To achieve the above object, the present invention also provides adesigning method of driver circuit for in-cell touch display panel,which comprises:

finding dark line locations of all horizontal scan lines of the touchdisplay panel according to a preset timing sequence;

setting a mask condition, designing the horizontal scan linescorresponding to the dark line locations to be driven synchronously by afirst GOA circuit and a second GOA circuit, and the remaining horizontalscan lines being driven by only the first GOA circuit;

the first GOA circuit and the second GOA circuit have a thrust passingsimulation confirmation in advance.

In a preferred embodiment, the first GOA circuit and the second GOAcircuit are located respectively at two opposite sides of the touchdisplay panel.

In summary, the driving method, driver circuit and design method ofdriver circuit for in-cell touch display panel provided by the presentinvention solve the dark line problem appearing in the time-sharingscanning between display and TP terms in the in-cell touch displaypanel, and improve display quality.

BRIEF DESCRIPTION OF THE DRAWINGS

To make the technical solution of the embodiments according to thepresent invention, a brief description of the drawings that arenecessary for the illustration of the embodiments will be given asfollows. Apparently, the drawings described below show only exampleembodiments of the present invention and for those having ordinaryskills in the art, other drawings may be easily obtained from thesedrawings without paying any creative effort. In the drawings:

FIG. 1 is a schematic view showing the driving timing sequence for aknown in-cell LCD;

FIG. 2 is a schematic view showing the dark line appearing after TPscanning for a known in-cell LCD;

FIG. 3 is a schematic view showing the gate signal transmitted in aknown in-cell LCD;

FIG. 4 is another schematic view showing a known GOA single-sidedcircuit;

FIG. 5 is a schematic view showing the flowchart of the driving methodfor in-cell touch display panel provided by an embodiment of the presentinvention;

FIG. 6 is a schematic view showing the driver circuit for in-cell touchdisplay panel provided by a preferred embodiment of the presentinvention;

FIG. 7 is schematic view showing the data transmission after compensatedby the driving method for in-cell touch display panel provided by apreferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To further explain the technical means and effect of the presentinvention, the following refers to embodiments and drawings for detaileddescription.

Refer to FIG. 5. The present invention provides a driving method forin-cell touch display panel, which comprises:

Step 10: connecting all horizontal scan lines of the touch display panelto a first GOA circuit, and the first GOA circuit performing displayscanning according to a preset timing sequence. For the known in-celltouch display panel, the preset timing sequence can be as shown in FIG.1, i.e., comprising time-sharing between touch panel scanning anddisplay scanning. In the present invention, the touch display panel canbe any in-cell touch display panel, such as, hybrid in-cell touchdisplay panel or full in-cell touch display panel.

Step 20: after completing each time of touch panel scanning according tothe preset timing sequence, a first horizontal scan line in a followingscanning according to the preset timing sequence being still connectedto a second GOA circuit, the second GOA circuit and the first GOAcircuit synchronously performing display scanning to the firsthorizontal scan line.

The thrust of the first GOA circuit and the second GOA circuit can passsimulation confirmation in advance, such as, luminance simulation andpanel layout circuit simulation of the optical portion of the touchdisplay panel.

The present invention begins with increasing the GOA thrust of thedisplay column with dark lines to solve dark line caused by theinsufficient charge of the gate signal due to current leakage. A shownin FIG. 4, the known gate driving structure for small-to-medium size LCDis mostly single-sided GOA driving, and the present invention usesdoubled-sized driving for the dark lines with serious current leakage toincrease the thrust to improve the charging capability, leading toimproved luminance.

Refer to FIG. 6. FIG. 6 is a schematic view showing a preferredembodiment of the driver circuit for the in-cell touch display panel,which comprises: which comprises: a first GOA circuit 11, and a secondGOA circuit 12; the first GOA circuit 11 being connected to allhorizontal scan lines of the touch display panel, and performing displayscanning according to a preset timing sequence; and after completingeach time of touch panel scanning according to the preset timingsequence, a first horizontal scan line in a following scanning accordingto the preset timing sequence being still connected to the second GOAcircuit 12, the second GOA circuit 12 and the first GOA circuit 11synchronously performing display scanning to the first horizontal scanline. In this preferred embodiment, the first GOA circuit 11 and thesecond GOA circuit 12 are located respectively on two opposite sides ofthe touch display panel to simplify the routing layout.

Also refer to FIG. 6. For the time-sharing scanning in-cell touchdisplay panel, each first line after completing TP scanning has a darkerdisplay. Because TP scanning is suspended A times, the entire screenwill show A−1 dark lines. If N lines are displayed each time, the A−1dark lines appear at (N+1)-th line, (2N+1)-th line, . . . ,((A−1)N+1)-th line. The present invention only needs to performdouble-sided driving for those suspended lines. For example, for a 5-inphone display with a 1080*1920 resolution, a TP scanning is performedfor every displaying of 120 lines, which requires 15 suspensions.Therefore, the second GOA circuit 12 is added to the right side of thescreen to drive these 15 scan lines.

The present invention also provides a designing method of driver circuitfor in-cell touch display panel, which comprises:

(1) finding dark line locations of all horizontal scan lines of thetouch display panel according to a preset timing sequence. For thein-cell touch display panel performing scanning according to presettiming sequence, each first line after completing TP scanning has adarker display. Because TP scanning is suspended A times, the entirescreen will show A−1 dark lines. If N lines are displayed each time, theA−1 dark lines appear at (N+1)-th line, (2N+1)-th line, . . . ,((A−1)N+1)-th line.

(2) setting a mask condition, designing the horizontal scan linescorresponding to the dark line locations to be driven synchronously by afirst GOA circuit and a second GOA circuit, and the remaining horizontalscan lines being driven by only the first GOA circuit. Compared to theknown single-sided driving, the present invention uses double-sideddriving for GOA circuit for the gate lines with dark line, and usessingle-sided driving for the remaining gate lines.

(3) the thrust of the first GOA circuit and the second GOA circuit canpass simulation confirmation in advance, such as, luminance simulationand panel layout circuit simulation of the optical portion of the touchdisplay panel.

Refer to FIG. 7. FIG. 7 is a schematic view showing the datatransmission after compensated by the driving method for the in-celltouch display panel of the present invention. Comparing FIG. 7 and FIG.3, it is shown that the present invention has avoided the signaldistortion and the rising and falling edges are no longer delayed. Thepresent invention, by increasing the GOA thrust of the lines with darklines, solves the dark line problem caused by the insufficient chargingdue to Gate signal current leakage. By compensating the dark linesgenerated by the current leakage because of the suspension for TPscanning, the display quality if improved.

In summary, the driving method, driver circuit and design method ofdriver circuit for in-cell touch display panel provided by the presentinvention solve the dark line problem appearing in the time-sharingscanning between display and TP terms in the in-cell touch displaypanel, and improve display quality.

It should be noted that in the present disclosure the terms, such as,first, second are only for distinguishing an entity or operation fromanother entity or operation, and does not imply any specific relation ororder between the entities or operations. Also, the terms “comprises”,“include”, and other similar variations, do not exclude the inclusion ofother non-listed elements. Without further restrictions, the expression“comprises a . . . ” does not exclude other identical elements frompresence besides the listed elements.

Embodiments of the present invention have been described, but notintending to impose any unduly constraint to the appended claims. Anymodification of equivalent structure or equivalent process madeaccording to the disclosure and drawings of the present invention, orany application thereof, directly or indirectly, to other related fieldsof technique, is considered encompassed in the scope of protectiondefined by the claims of the present invention.

What is claimed is:
 1. A designing method of a driver circuit for anin-cell touch display panel, comprising the following steps; findingdark line locations of all horizontal scan lines of the in-cell touchdisplay panel according to a preset timing sequence; setting a maskcondition, designing the horizontal scan lines corresponding to the darkline locations to be driven synchronously by a first gate on array (GOA)circuit and a second GOA circuit, and the remaining horizontal scanlines being driven by only the first GOA circuit, wherein the horizontalscan lines corresponding to the dark line locations are connected to anddriven by both the first and second GOA circuits, while the remaininghorizontal scan lines are connected to the first GOA circuit only to bedriven only by the first GOA circuit; and the first GOA circuit and thesecond GOA circuit have a thrust passing simulation confirmation inadvance.
 2. The designing method as claimed in claim 1, wherein thein-cell touch display panel is a hybrid in-cell liquid crystal display.3. The designing method as claimed in claim 1, wherein the in-cell touchdisplay panel is a full in-cell liquid crystal display.
 4. The designingmethod as claimed in claim 1, wherein the first GOA circuit and thesecond GOA circuit are located respectively at two opposite sides of thein-cell touch display panel.